PWS is a complex genetic disorder that includes short stature, mental retardation or learning disabilities, incomplete sexual development, characteristic behavior problems, low muscle tone, and an involuntary urge to eat constantly, which, coupled with a reduced need for calories, leads to obesity.

Does bypass surgery lead to a reduction in appetite?

Yes. It disrupts the secretion of ghrelin by disrupting communication between the upper intestine and the stomach or by damaging afferent axons in the vagus nerve.

What chemicals/n.t. tells you to eat and where are they ?

- Ghrelin (stomach)- MCH and Orexin (lateral hypothalamus)- NPY (neuropeptide Y, found in arcuate nucleus in the base of the hypothalamus)

When the stomach empties ghrelin secretion _____ ?

increases

Decrease in what chemical/n.t. variables contribute to satiety?

-low ghrelin, NPY, MCH, and orexin

Decrease in what non chemical/n.t. contribute to satiety?

-stimuli that have been associated with "fullness" due to experience lead to a conditioned response (learning) of feeling full, taste, texture, smeels, sight, stop eating before we actually get change in blood glucose

What neurons in the arcuate N. inhibit eating?

CART and a-MSH

Obese people with low levels of this hormone show significant weight loss if given a certian kind of therapy... ?

Leptin, leptin therapy.

Most obese people have high levels of this kind of hormone and its receptors?

When fats are detected in the small intestine what is released and what does it do?

Cells in the small intestine release CCK (cholecystokinin) when fats are detected and this reduces eating by being detected in the vagus nerve and sending info to the brainstem. - Rats lacking CCK receptors become obese.